Collaborative Research: Climatic Control of Erosion Rates and Landscape Morphology - Quantifying the Influence of Fluvial Thresholds

合作研究：侵蚀率和景观形态的气候控制 - 量化河流阈值的影响

• 批准号: 2229224
• 负责人: Darryl Granger
• 金额: $ 10.89万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2229224&HistoricalAwards=false
• 关键词: Collaborative; Research; Climatic; Control; Erosion

This project seeks to advance understanding of land surface response to climate change through study of evolving landforms on the Hawaiian islands. This research will improve scientists’ ability to decipher the record of past climates from landforms and to anticipate land surface response to future climate change. Planned research activities focus on the role of extreme events in canyon cutting – a topic that is central to landscape response to climate change but has received insufficient attention. The team will recruit two undergraduates from underrepresented communities in Hawaii to participate in the research effort and to attend an international professional conference to learn about opportunities and establish network connections. Outreach and hands-on public educational activities will be developed at both Arizona State University and the University of Indiana, including through participation of undergraduates in research efforts. All resulting research data will be made publicly available.This research will extend prior studies of the Hawaiian islands by examining landscapes across a span of islands, and thus landscape ages, and across the dramatic differences in rainfall between windward and leeward slopes, emphasizing the role of geomorphic thresholds and the extreme events that can exceed them. Preliminary investigation indicates that the kilometer-deep canyons common to all of the islands were cut rapidly to depths similar to the present day, after which incision stagnated because channel gradient decreased below a climate-dependent threshold for moving large boulders in channels. This study will systematically test the hypothesis that canyon cutting on the Hawaiian islands has been limited by boulder transport thresholds. A combination of methods will be deployed, including detailed field measurements, digital elevation model analyses, 40Ar/39Ar dating of inset lava flows, and estimates of catchment-mean erosion rates from cosmogenic 36Cl in magnetite in river sediment – a novel method only recently developed. This research represents an opportunity to advance understanding of climatic control on landscape evolution in general, and to quantify how fluvial incision thresholds critically modulate connections among climate, topography, and erosion rate. The Hawaiian islands provide unique conditions to directly measure fluvial thresholds and to quantitatively assess their role modulating climatic control of landscape evolution.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目旨在通过研究夏威夷群岛不断变化的地貌来增进对地表对气候变化的响应的了解。这项研究将提高科学家从地貌中破译过去气候记录并预测地表对未来气候变化的反应的能力。计划的研究活动重点关注极端事件在峡谷切割中的作用——这是景观对气候变化响应的核心主题，但尚未得到足够的关注，该团队将从夏威夷代表性不足的社区招募两名本科生来参与研究工作并进行研究。出席亚利桑那州立大学和印第安纳大学将举办一次国际专业会议，以了解机会并建立网络联系，包括通过本科生参与研究工作，所有由此产生的研究数据都将被公开。这项研究将通过对整个岛屿的景观检查来扩展之前对夏威夷群岛的研究，从而检查景观年龄，以及迎风坡和背风坡之间降雨量的巨大差异，强调地貌阈值和极端情况的作用可以超过的事件初步调查表明，所有岛屿共有的千米深的峡谷被快速切割至与现在相似的深度，此后切割停滞，因为河道梯度低于研究中大型巨石的气候阈值。将系统地检验夏威夷群岛峡谷切割受到巨石迁移阈值限制的假设，将采用多种方法，包括详细的现场测量、数字高程模型分析、40Ar/39Ar 测年。嵌入熔岩流，以及河流沉积物中磁铁矿中宇宙成因 36Cl 的流域平均侵蚀率的估计——这是最近才开发的一种新方法，这项研究为增进对气候对景观演化的控制的理解和量化提供了机会。河流切割阈值如何关键地调节气候、地形和侵蚀率之间的联系夏威夷群岛提供了独特的条件来直接测量河流阈值并定量评估其调节气候控制景观演变的作用。通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。